The 1000$ estimate is taken mainly from his proposal:
This doesn't have to be expensive. A common setup winds up being two 6VDC golf cart batteries in series (12 volts total), 2-3 PV panels, a decent charge controller , and an inverter. This won't run your air conditioner unit, but it will be big enough to handle a number of low amperage devices, and one can build a decent setup for well under $1000.
This number did not include wiring to point of use, fuses, sockets, etc. All of which would be AC in the proposed solution (read: the installer should understand electricity to be safe).
For the umpteenth time - I am not bashing solar as such. I have NOT said you should not use solar panels. I have NOT said that you can not save money by solar. You are arguing against something i have not said, repeatedly.
What I am saying, is that making a duplicate wiring is stupid. If you are doing solar and are using an inverter, why not feed it into the existing AC system? This will cost less than duplicate wires/fuses/sockets. You will have all the benefits described and you will use all of the produced energy (more savings) for less money. You can plug vacuum cleaner into any socket without bloring the fuse (or your inverter).
On the other hand - if you wanted to use solar just to power phone chargers, it would be much, much cheaper to ditch the DC/AC/DC converting process and charge your phones from the 12V batteries via voltage regulator to 5V without an inverter ol wall/warts.